For my current generation systems, I have this attitude towards them:
X360 - For anything even remotely close to the First Person Shooter (Halo, Battlefield, Borderlands, etc) and mostly the 3rd person action/adventure/RPG game (Resident Evil, Gears Of War, Walking Dead, Dragon Age, Elder Scrolls, etc) as well as hybrid 3rd/First person game (Mass Effect, etc) genres due to the excellent online matchmaking and ease of use for local and online multiplayer games. Sometimes used to watch Netflix, although the Netlfix interface is a bit awkward to use. Sometimes used to watch Digital Copies of films that I uploaded to my collection of USB flash drives.
PS3 - For any software titles that are purely 3rd person action games as well as fighting games (Bayonetta, DMC, Marvel VS Capcom, Mortal Kombat, Injustice, etc.) Online play is mostly non-existent for my usage due to running into 'mostly' cheaters who hack the games, etc. . To top it off, the PS3 "XMB" navigation is very clumsy to use (finding stuff in the Playstation Store is awkward) when compared to the easier to use X360 interface. The PS3 is also the only Blu-Ray player I have in the house. (Once DVDs are phased out and everything is only on Blu-Ray, I'll make the jump to a stand-alone Blu-Ray player.) Rarely used to watch Netflix or browse the internet due to seemingly 'endless' updates to the firmware or Netflix itself. Also used more often to watch Digital Copies of films that I uploaded to my collection of USB flash drives. (If the X360 can't play the video file, the PS3 usually can)
Wii - Pretty much now only used to stream Netflix due to the very easy to use interface utilizing the Wii Remote and watch some Youtube videos on occasion.
PSP - I'm not interested in a PS Vita (aka a portable PS3) so I still use my PSP on occasion. PSP is mostly used to view movies ripped from my DVD collection.
3DS XL - Used fto play many different games due to the Virtual Console games that are available as well as my vast library of DS and 3DS games. Also used to browse the internet and watch Netflix when I'm too lazy to sit on the couch (mostly right before I go to bed, I'll catch an episode of Star Trek TOS or maybe MacGyver.)
DSi XL - Used exclusively for DS games (Pokemon Black, White V2, etc.) as well as the DSiWare games.
So what do you all use your current gen systems for and what will plan on using your Wii U, PS4 or XBox One for, besides playing games?